A conventional device for determining a position which uses a Global Positioning System (G.P.S.) is well known. In such a system, a person can determine the longitude and latitude of his or her position by receiving radio signals from a plurality of satellites with a G.P.S. receiver. The person can determine his or her position by comparing a map with the longitude and latitude information from the receiver. One example of such a well known system is a commercially available LORAN navigation system.
A conventional driving guide system for a vehicle (such as a car) is known which uses a G.P.S. receiver in connection with map data stored on a CD-ROM memory media. The position from the G.P.S. receiver is compared by a computer with map data from a CD-ROM, and the position is indicated on a display together with the map data from the CD-ROM. Accordingly, one's position can be easily recognized on a display. An example of such a system is the commercially available Bosch travelpilot. One problem with such a system is that it is necessary to use an expensive memory media (e.g., CD-ROM) which can store a large quantity of map information.
U.S. application Ser. No. 07/789,831, entitled "Position Recognition System and Position-Coordinate Converting Device", fried Nov. 8, 1991, incorporated herein by reference, discloses an apparatus for inexpensively displaying positional information to a user comprising a position-coordinate converting device including position detecting means, map information storage means, and coordinate operation means for operating on area information based on the results of the position detecting means and the map information stored in the map information storage means. The disclosed apparatus allows the user to make use or a conventional paper map which is divided into square areas, each of which may be further subdivided into smaller units. The disclosed apparatus displays to the user his or her position in relation to the paper map using a much more limited map database which can, for example, be stored on a "smart card" integrated circuit device which is much smaller and cheaper than a CD-ROM storage device.
Using the previously disclosed apparatus, the user is provided with positional information in relation to data which can be viewed on a conventional paper map without the need to store an entire copy of the paper map in the apparatus itself. For example, a display may be presented to the user which indicates the page number corresponding to a paper map square area and, further, more detailed coordinates within a square area such as (A. 1-1.2),(B.2-1.2) based on the user's current position. This method provides a very inexpensive way of allowing the user to find his or her location on a paper map without the need to store a large quantity of map data on a CD-ROM, yet still supplies information to the user in a form which is more efficient than a mere latitude/longitude location, which would require that the user translate this into a paper map location. With the construction described above, the user can recognize the position of the vehicle readily by comparing area information displayed on the vehicle travel guide apparatus with the paper map. Further, position information of a destination or the like can be input readily to the vehicle travel guide apparatus.
The applicant of the present invention has proposed a vehicle travel guide system and a vehicle travel guide apparatus in Japanese Patent Application No. 2-303404 and a position information inputting apparatus for a vehicle travel guide system in Japanese Utility Model Application No. 3-373.
The vehicle travel guide system disclosed in Japanese Patent Application No. 2-303404 comprises a paper map and a vehicle travel guide apparatus, the paper map being divided into a plurality of areas each having corresponding area information, the vehicle travel guide apparatus including position information inputting means for inputting position information of at least one destination, position information storage means for storing the position information therein, position detecting means for detecting the position of a vehicle, map information storage means for storing therein information of the plurality of areas of the paper map as map information, calculating means for producing area information of the map corresponding to the position of the vehicle and travel guide information from a result of the detection of the position detecting means and the map information stored in the map information storage means, and display means for displaying a result of the calculation of the calculating means. The position and a travel route of the vehicle may be recognized by the user's comparing the result of the calculation displayed on the vehicle travel guide apparatus with the area of the paper map.
The position information inputting apparatus for a vehicle travel guide system disclosed in Japanese Utility Model Application No. 3-373 is an apparatus adapted to be placed on a paper map which is divided into a plurality of areas of a same rectangular shape and having corresponding area information for each area. The apparatus, which allows a user to input position information of a designated spot in one of the areas into the vehicle travel guide apparatus, comprises a flat plate-shaped body having a window of a shape corresponding to one of the areas and having a shape a little greater than one of the areas, area selecting means for selecting one of the plurality of areas, designated area detecting means for dividing the inside of the plane of the window into a plurality of small division areas and for detecting that one of the small division areas is designated by a finger or the like, information storage means for storing therein area information corresponding to each of the areas and small division area information corresponding to each of the small division areas, and information sending means for sending out the area information of the selected area and the small division area information of the designated small division area to the vehicle travel guide apparatus in accordance with a result of the detection of the designated area detecting means and the information stored in the information storage means. This provides a means of inputting position information of a destination or the like into the vehicle travel guide apparatus by placing the information inputting apparatus on the paper map.
With the disclosed apparatus, however, there remains a problem that the input means and display means may be inadequate for the user. For example, a beginner using the system for the first time may require a substantial amount of time to learn how to use the system. Moreover, the displayed information may be insufficient to allow the user to easily navigate with reference to a paper map. The user may not be able to efficiently enter one or more destinations into the apparatus for subsequent computation and display.